The primary objective of this project is to investigate the problems of neuromuscular control in speech production of neurologic patients. These speech disorders are classified as the dysarthrias. Previously, the neuromuscular bases for a particular dysarthria have been inferred from the (1) neuromuscular condition as determined from the neurologic examination, and (2) perception of certain speech and voice characteristics that are usually associated with the specific disorder. To our knowledge, the present research is the first to incorporate systematic physiologic study of these speech mechanisms is a large number of dysarthric patients. The design of individual experiments is intended to produce data that can be related to a specific aspect of neuromuscular control. Subject performance on the set of experiments is then integrated into hypotheses concerning the total neuromuscular condition as it affects the individual's speech. As a secondary objective, we are experimenting in the rehabilitation of dysarthria. The treatment strategy for the patient is based on the descriptive data obtained in the physiological studies referred to above. In addition, the patient's response to a particular treatment is often useful in furthering knowledge of the particular neuromuscular mechanisms that underlie the specific dysarthria.